X campbell



3 Sheets-Sheet 1.

Patented July smssa.

I N V N TO R By his- ./1tiorneys,

A. CAMPBELL. GRINDING MACHINE.

(No Model.)

A ,m HRH N. PETERS. mwumgnpw. Wahinginn. n, a

WITNESSES? (No Model.)

3 Sheets-Sheet 2.

A. CAMPBELL. GRINDING MACHINE.

Patented'July 31 1883) IN'VENTOR:

WITNESSES:

w m a Q, vii/W- M N PETERS, Phafio-Lillwgnphll, wilhingion, D. Q

(No Model.)

3 Sheets-Sheep 3.

A. CAMPBELL.

GRINDING MACHINE.

. 7? rt A Patented July 31, 1883.

INVENTOR:

WITNESSES:

N PETERS. mmmhn n m. wningun. n. c.

UNITED STATES PATENT OFFICE.

ANDREW CAMPBELL, OF BROOKLYN, ASSIGNOR 'IO JOHN AND EDMUND MCLOUGHLIN,OF NEW YORK, N. Y.

MA'CHIN'E.

SPECIFICATION,forming part of Letters Patent No. 282,049, dated July 31,1883 A Application filed April 30, 1883. (No model.)

Toctll whom it may concern Be it known that I, ANDREW CAMPBELL, acitizen of the United States, residing at Brooklyn, Kings county, NewYork, have invented certain Improvements in Grinding-Machines, of whichthe following is a specification.

My invention relates to a machine designed, primarily, for grinding downand facing lithographic stones and bringing them to a uniform thicknes;but it may be employed for other analogous purposesas for example, intruing up the faces of stones for other uses, and in grinding the facesof metal or glass plates. The stone or other thing to be ground ismounted on a revolving face-plate, and the rotating grinder is fedacrossits face and up to it by means of a cross'feed mechanism constructedsimilar to the cross-feed of an ordinary'metal lathe. The grinder has aface in the form of a very flat'cone, the angle of which need not exceedone degree, and the axis of'the grinder, which is ,in the axis of thecone, is set at an angle with the axis of the face-plate which bears thestone or other thing being ground, this angle corresponding with theangle of the coneof the grinder. Thusthe grinder presents to the surfaceto be ground a face that is nearly flat, and of course continuous, theeffect being much the same as that produced with a broad grindstone ofseveral hundred feet in diameter. Through the hollow axis of the grinderare introduced suitable abrading substances-as sand, glass, or emeryandwater or other liquid. Novel means are provided for insuring a positiveand accurate cross feed, and for clamping the stone or other thing to beground to the face-plate, all as will be hereinafter more fullydescribed.

Another important feature of my invention is the grinding of the face ofa lithographic stone by the application to its face of arotary grinder,while the stone itself is made to rotate with the face to be groundarranged in a vertical or nearly vertical plane. Stones of thischaracter must have perfectly plane faces, and I find this method ofgrinding especially well adapted for producing perfect results. ,Isupport the stone in a rotating holder or chuck, so that it stands upedgewise, whereby all tendency to sag in the center as it revolves isentirely avoided.

In the drawings, which serve to illustrate my invention, Figure 1 is aplan of my improved grinder, the face-plate and grinder being inhorizontal midsection. Fig. 2 is a side elevation. Fig. 3is across-section, drawn to a scale double that of Figs. 1 and 2, throughthe axis of the grinder, substantially on lines 3 3 in Figs. 1 and 2.Fig. 4 is a view of the side of the machine opposite to that in Fig. 2.

Fig. 5 is a front view of the conical-faced 'The counter-shaft isdrivenfrom the main shaft through the medium of a belt, K, which Figs.10 and 11 illustrate modifications.

connects the two sets of cone-pulleys, as shown in Fig. 1.

L represents the bearing-frame, uponwhich is mounted a slide orcarriage, M. is operated automatically by means of a gearwheel, a, onthe main shaft, which meshes with another gear-wheel, I), mountedrotatively on a stud, c, in the frame L. Secured to wheelb is amiter-wheel, d, which meshes with one or the other of the miter-wheels eand e,connected together and splined on the end of the feedscrew N,which engages a nut, f, (shown only in Fig. 3,) on the carriage M.Rotation of the main shaft B imparts slow rotary motion to theface-plate I, and a reciprocating motion to the slide or carriage M onthe bearings or shears L. This reciprocating movement is produced bymeans of mechanism I will now describe with reference to Figs. 1 and 4.As before stated, the miter-wheels e and c are connected This slidetogether by a circumferentially-grooved sleeve,

g, and are splined on the screw N. By sliding them 011 the screw eithermay be made to engage the wheel (I, and thus the rotary motion of thescrew be reversed. In order to effect this reversal automatically, Iprovide a fork, h, to engage the groove in the sleeve 9, and secure thisto a shaft, 13, mounted to oscillate in a suitable bearing on L. To theouter end of this shaft I secure a weighted arm, j, and this I couple toa shifting-rod, 7a, 011 which are adjustably fixed collars Z l in thepath of the carriage M. Thus when the carriage reaches the end of itsmovement it strikes the collar, and through rod 7c shifts the gears e.e. This is a well-known shifting device, and I make no specific claim toit. Other well-known devices may be employed in lieu of this, or theshifting may be effected by hand.

O is a carriage or slide mounted in guides or keepers on the slide M,and adapted to be moved on the same transversely of the slide M and atright angles to the axis of the feed-screw N-that is to say, in a planeparallel to the axis of the shaft H, which bears the face-plate I. Onthe carriage O is rotatively mounted a hollow shaft, P, which bears thegrindinghead. This latter comprises a chuck or holder, Q, and theconical grinder R. This grinder may be of stone,'emery, or any suitableabrading or polishing material adapted to the purpose. I make its faceconical, as shown in Figs. 1 and 3, preferably employing an angle ofonly one or two degrees with the base, or eighty-eight to eightyninedegrees with the axis of the cone. In order to bring the face of thecone on one side (as in Fig. 1) parallel to the face of the stone orother article, S, being ground,

"I mount the shaft P obliquely with the axis of shaft H as respects thevertical plane; but the two are aligned in the horizontal plane. Thisgives a clearance on the opposite side, (y in Fig. 1,) as clearly shown.The coned grinder is thus made to present practically a nearly fiat faceto the stone S, and a continuous surface moving always in one direction.As the stone S moves slowly on its axis and the rotating grinder R playsback and forth .across its surface, every part of the surface of thestone will be subjected to the same abrading action. In order to impartat once a reciprocating and a rotary movement to the grinder, I providethe mechanism I will now describe, with reference particularly to Fig.2.

T is an endless belt, which passes over apulley, U, on the main shaft B,guide-pulleys V V on the frame of the machine, a pulley, WV, on thegrinder-shaft P, and a guide-pulley, X, on the carriage O. Thisarrangement permits, as will be understood without further explanation,the driving of shaft P from the main shaft without slackening belt T, inwhatever position the carriages M and 0 may stand.

It is important that the cross-feed mechanism, whereby the carriage O ismoved, and whereby the grinder R is fed up to the stone S, shall be verypositive in its action and sen sitive to the slightest movement of thecrossfeed screw. To accomplish this I provide the said screw withappliances clearly shown in Fig. 3, wherein m is the cross-feed screw,mounted in the carriage M, and provided with a suitable crank, 42.. Toprevent any end-play in its bearings, due to wear, this screw isprovided with afixed collar, 0, inside of the bearing, a loose collar,0, outside the bearing, an adjusting-nut, p, and a spring, q. The springmust have strength sufficient to overcome the resistance offered by thecarriage O. This device provides against lost motion in thescrewbearings. To guard against lost motion in the nut on the carriage Othe following de scribed device is employed: Y is a tubular shellsecured to the under side of the carriage O, and 1' is a nut, internallyand externally threaded, which screws into the end of Y, and also screwsonto the feed-screw m. This nut is provided with a set-nut, r. Inthe-other end of the shell Y is splined a tubular nut, s, which alsoscrews onto the feed-screw m, and between the nuts 1" and s is arrangeda spiral spring, 25. This spring may be adjusted to any tension requiredby screwing in the nut 1". This tension must be sufficient to resist anyopposition due to the inertia of the carriage O. The tubular shell neednot extend over the spring t and nut 8, except in so far as to provide asplined attachment for the nut s to carriageO to prevent it from turningwith the screw; but as constructed the springs and nuts are housed andprotected from dirt. A set-screw might be substituted for the nut r.Fig. 10 illustrates this construction.

Fig. 3 illustrates the means for supplying the grinder R with sand andwater or other grit and liquid. Through the hollow of shaft P extends atube, a, which has bearings at o o in shaft P, and opens into acentralcavity, 10, in the grinder. This tube a does not rotate with shaft P,and is provided with a receiver or holder, Z, for the grit, and a hoseor pipe, 2, to lead the water or other liquid from the supply to thetube a. From the rear end of tube a depends a branch, a, with an eyewhich engages a stud, b, on the carriage 0. Behind this arm is a spring,0. Thispermits the pipe u to be moved longitudinally on its bearings, sothat the bearing 1), which is in the nature of a rawhide-piston, may begot at for oiling. This tight-fitting piston prevents water and gritfrom getting into the shaft P and at the bearings. Spring 0 retracts theparts. On the end of pipe at is a species of head or nozzle, '0 with arecess at '0 in its lower lip to prevent the water and grit from workingback into the bearing. This is not very important; but the recess orgroove at the lower side of the lip, where the gritty liquid is apt tocollect, serves in some degree as a barrier to prevent the liquid frombeing carried back by capillary attraction to the bearing in the shaftP.

I will now describe my improved chuck or IIO clamp which I employ hereinfor holding the clamp bolts, in the manner of an ordinaryclamping-chuck. The clamping-jaw e of the chuck is penetrated by anaperture or cylindrical bore, f, arranged obliquely and opening out atthe top and face of the jaw, as shown in Fig. 6, which is a verticalsection on line 6 6 in the plan, Fig. 7. This bore f receives a tooth ordog, 9, (shown detached in Fig. 8,) which has its ends beveled, asindicated. A screw, h, screws through the jaws e from the back andimpinges upon the beveled upper end of the tooth g, which is presentedto it at right angles. The lower sharp end of the tooth projects fromthe face of the jaw adjacent to the stone S and bites into the same whenh is brought to bear against its upper end. The

pressure on the stone being oblique, it will be seen that the stone willbe pressed up firmly to its bearings cl on the face-plate, as well asheld between the converging jaws of the clutch,

I prefer to make the teeth 9 from a cylindrical bar of steel 5 but theymay be made from square or polygonal bars as well. i

Fig. 9 is a cross-section on line 9 9 in Figs. 6 and 7, showing the slotin d.

Fig. 11 illustrates a modification of my improved clamping-jaw. In thisconstruction screw h does not impinge directly upon the end of tooth 9,but upon afollower, g", whichplays in a bore, f and which has a beveledextremity that impinges on'the beveled upper end of g. The constructionand operation will be obvious from inspection of Fig. 11.

I do not limit myself to the precise arrange.- ment of the parts hereinshownfor example, the shafts H and P may stand vertical or inclinedinstead of horizontal, as shown, in facing off metals or other surfaceswhere perfect accuracy is not required. For grinding the faces oflithographic stones, however, the stone should stand with the face to beground in a vertical or nearly vertical plane. The shaft I" might alsobe mounted on its carriage O, with its axis parallel to the path inwhich said carriage moves transversely across M, and the said carriage 0be mounted to stand and move obliquely on the carriage M. This wouldgive the shaft P its proper obliquity.

The grinder B may be constructed of the proper shape and then set in theholder Q by screws or cement, or it may be made from some suitablecomposition, as emery, sand, and hydraulic cement, and molded directlyin the holder. The grinder need not be fed past the center of the stoneS; indeedI prefer it should not, as in that case the two would move inthe same direction, which is objectionable. The arrows in Figs. 1 and2illustrate the direction in which the rotating parts move.

I provide the face-plate I with a raised cuplike flange, t, as shown inFig. 1, to act as a guard and prevent the gritty liquid from beingthrown off and among the machinery. Instead of being mounted to rotate,this faceplate might be arranged to reciprocate, or it might bestationary and the grinder be arranged to move over its entire surface.

Having thus described my invention, I claim- .1. A grinding-machinecomprising a suitable faceplate or chuck to hold the object to beground, a grinder having a slightly-conical face mounted rotatively onan oblique axis, substantially as shown, and a feeding mechanism,substantially as described, for feeding said cone-faced grinder over theface of the object to be ground, substantially as set forth.

2. The combination, in a grinding-machine, of a face-plate to hold theobject to be ground, mounted rotatively, a conical-faced grinder mountedrotatively on an axis oblique to the axis of the face-plate, andmechanism, substantially as described, for imparting a rotary motion tosaid face-plate and grinder, and for feeding the grinder up to andacross the face of the object to be ground, substantially as and for thepurposes set forth.

3. The combination, in a grinding-machine, of the face-plate I and itsshaft H, the carriage M, mounted to slide on the frame or shears L,parallel with the face of the faceplate I, the carriage O, mounted toslide on the'carriage M, and transversely thereof, the grinder R, with aconical face, mounted in a holder, Q, and the grinder-shaft I, mountedobliquely on the carriage O to a degree that will bring the face :0 ofthe grinder into a plane parallel to the face of the face-plate I,substantially as set forth.

4. The cross-feed screw m, provided with a fixed collar, 0, a loosecollar, 0, an adjustingnut, 10, and spring q, substantially as setforth.

5. The combination, with the carriage O and screw m, of the shell Y,secured to carriage O, the nuts r and s, and the spring t, arrangedbetween them,-substantially as and for the purposes set forth.

6. The combination, with the carriage O, of the screw an, provided withthe tight and loose collars 0 o, the nut p, and spring q, and the shellY, nuts r and s, and the spring 2, all arranged substantially as setforth.

7. The combination of the hollow grindershaft and the grinder, the tubeu, provided with bearings in the hollow'of the grindershaft, the holderor hopper Z for the grit, and the pipe z, supplying water or otherliquid, substantially as set forth.

8. As a clamp for holding the object to be ground, a block orsocket-piece provided with an oblique bore, f, to receive the tooth, theIn witness whereof I have hereunto signed said tooth g and the screw hfor setting the my name in the presence of two subscribing toothsubstantially as set forth. witnesses.

9. A machine for grinding the faces of lith- V 5 ographic stonescomprising means for holding ANDREXV CAMPBELL.

the stone to be ground with its face to be ground in a substantiallyvertical plane, and means \Vitnesses: for rotating said stone while itis being ground, HENRY OONNETT, all constructed and arranged to operatesub- ARTHUR O. FRAsEP. I O stantially as set forth.

